package com.cn.wanxi.servlet;

import com.alibaba.fastjson.JSONObject;
import com.cn.wanxi.model.ImgModel;
import com.cn.wanxi.model.ResultModel;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.Date;
import java.util.List;
import java.util.Random;
import java.util.UUID;

@WebServlet("/upload")
public class UploadServlet extends HttpServlet {

    // 上传文件存储目录
    private static final String UPLOAD_DIRECTORY = "upload";

    // 上传配置
    private static final int MEMORY_THRESHOLD = 1024 * 1024 * 3;  // 3MB
    private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB
    private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50; // 50MB
//    private String fileName = "";
//    private String url = "";

    /**
     * 上传数据及保存文件
     */
    protected void doPost(HttpServletRequest request,
                          HttpServletResponse response) throws ServletException, IOException {
        // 检测是否为多媒体上传
        if (!ServletFileUpload.isMultipartContent(request)) {
            // 如果不是则停止
            PrintWriter writer = response.getWriter();
            writer.println(JSONObject.toJSONString(ResultModel.getModel("Error: 表单必须包含 enctype=multipart/form-data")));
            writer.flush();
            return;
        }

        // 配置上传参数,用来接收前端的文件保存的临时文件地址
        DiskFileItemFactory factory = new DiskFileItemFactory();
        // 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中
//        factory.setSizeThreshold(MEMORY_THRESHOLD);
        // 设置临时存储目录
//        factory.setRepository(new File(System.getProperty("java.io.tmpdir")));
//       文件解析器
        ServletFileUpload upload = new ServletFileUpload(factory);

        // 设置最大文件上传值
        upload.setFileSizeMax(MAX_FILE_SIZE);

        // 设置最大请求值 (包含文件和表单数据)
        upload.setSizeMax(MAX_REQUEST_SIZE);

        // 中文处理
        upload.setHeaderEncoding("UTF-8");

        // 构造临时路径来存储上传的文件
        // 这个路径相对当前应用的目录
        String uploadPath = request.getServletContext().getRealPath("./") + File.separator + UPLOAD_DIRECTORY;
        System.out.println(uploadPath);

        // 如果目录不存在则创建
        File uploadDir = new File(uploadPath);
//        if (!uploadDir.exists()) {
        uploadDir.mkdirs();
//        }

        try {
//            @Deprecated
            Date date = new Date();
            date.getTime();
            // 解析请求的内容提取文件数据
//            @SuppressWarnings("unchecked")
//                upload.parseRequest
            List<FileItem> formItems = upload.parseRequest(request);
//    formItems判断前端是否由文件传递过来
            if (formItems != null && formItems.size() > 0) {
                // 迭代表单数据
                for (FileItem item : formItems) {
                    // 处理不在表单中的字段,item.isFormField表示是否是文件
                    if (!item.isFormField()) {
//                        拿到当前的文件名称
                        String fileName = new File(item.getName()).getName();
//                        this.fileName = new Random().nextInt(10) +"-"+ fileName;
//                        this.fileName = System.currentTimeMillis() + "-" + fileName;
//                        重新对文件名进行赋值
                        fileName = UUID.randomUUID() + "-" + fileName;
//                        拼接保存到数据库的地址：注意一定要用绝对地址
                        String url = "/" + UPLOAD_DIRECTORY + "/" + fileName;
//                        保存到out里面的地址
                        String filePath = uploadPath + File.separator + fileName;
                        File storeFile = new File(filePath);
                        // 在控制台输出文件的上传路径
                        System.out.println(filePath);
                        // 保存文件到硬盘
                        item.write(storeFile);
//                        我们还需要再web里面去创建一个图片，否则当我们上传out文件时，文件不存在
                        String webPathString = uploadPath.split("out")[0] + "/web/";

                        File webPath = new File(webPathString, UPLOAD_DIRECTORY);
                        webPath.mkdirs();
                        File webFilePath = new File(webPath, fileName);
                        webFilePath.createNewFile();
// 我们可以将out里面的文件拷贝到web下面，其实就是一个读写
                        InputStream inputStream = new FileInputStream(storeFile);
                        OutputStream outputStream = new FileOutputStream(webFilePath);
                        int read = 0;
                        while ((read = inputStream.read()) != -1) {
                            outputStream.write(read);
                        }
//                        item.write(webFilePath);
//                        返回给前端的数据
                        ImgModel imgModel = new ImgModel();
                        imgModel.setSrc(url);
                        response.getWriter().println(JSONObject.toJSONString(ResultModel.getModel(imgModel)));
                    } else {
//                        表示是普通数据
                    }
                }
            }
        } catch (Exception ex) {
            response.getWriter().println(JSONObject.toJSONString("未上传文件"));
        }
//        // 跳转到 message.jsp
//        request.getServletContext().getRequestDispatcher("/message.jsp").forward(
//                request, response);
//        我们上传的格式必须为
        /**
         * {
         *   "code": 0
         *   ,"msg": ""
         *   ,"data": {
         *     "src": "http://cdn.layui.com/123.jpg"
         *   }
         * }
         *
         */


    }
}